diff --git a/src/clang_translation_unit.cc b/src/clang_translation_unit.cc
index 52639c98..88365f23 100644
--- a/src/clang_translation_unit.cc
+++ b/src/clang_translation_unit.cc
@@ -69,11 +69,7 @@ std::unique_ptr<ClangTranslationUnit> ClangTranslationUnit::Create(
     std::vector<CXUnsavedFile>& unsaved_files,
     unsigned flags) {
   std::vector<const char*> args;
-  for (const std::string& a : arguments)
-    args.push_back(a.c_str());
-
-  std::vector<std::string> platform_args = GetPlatformClangArguments();
-  for (const auto& arg : platform_args)
+  for (auto& arg : arguments)
     args.push_back(arg.c_str());
 
   CXTranslationUnit cx_tu;
diff --git a/src/platform.h b/src/platform.h
index 3e0fae2f..cbefb30e 100644
--- a/src/platform.h
+++ b/src/platform.h
@@ -42,7 +42,7 @@ void CopyFileTo(const std::string& destination, const std::string& source);
 bool IsSymLink(const std::string& path);
 
 // Returns any clang arguments that are specific to the current platform.
-std::vector<std::string> GetPlatformClangArguments();
+std::vector<const char*> GetPlatformClangArguments();
 
 // Free any unused memory and return it to the system.
 void FreeUnusedMemory();
diff --git a/src/platform_posix.cc b/src/platform_posix.cc
index 025ad074..12cb4a37 100644
--- a/src/platform_posix.cc
+++ b/src/platform_posix.cc
@@ -259,7 +259,7 @@ bool IsSymLink(const std::string& path) {
   return lstat(path.c_str(), &buf) == 0 && S_ISLNK(buf.st_mode);
 }
 
-std::vector<std::string> GetPlatformClangArguments() {
+std::vector<const char*> GetPlatformClangArguments() {
   return {};
 }
 
diff --git a/src/platform_win.cc b/src/platform_win.cc
index 608cf96e..87667d8d 100644
--- a/src/platform_win.cc
+++ b/src/platform_win.cc
@@ -129,12 +129,13 @@ bool IsSymLink(const std::string& path) {
   return false;
 }
 
-std::vector<std::string> GetPlatformClangArguments() {
+std::vector<const char*> GetPlatformClangArguments() {
   //
   // Found by executing
   //
   //   $ clang++ -E -x c++ - -v
   //
+  // https://clang.llvm.org/docs/MSVCCompatibility.html
 
   // clang-format off
   return {
diff --git a/src/project.cc b/src/project.cc
index 35d86aab..3bec6f1a 100644
--- a/src/project.cc
+++ b/src/project.cc
@@ -27,6 +27,8 @@
 #include <unordered_set>
 #include <vector>
 
+extern bool gTestOutputMode;
+
 struct CompileCommandsEntry {
   std::string directory;
   std::string file;
@@ -193,6 +195,12 @@ Project::Entry GetCompilationEntryFromCompileCommandEntry(
   if (!AnyStartsWith(args, "-working-directory"))
     result.args.emplace_back("-working-directory=" + entry.directory);
 
+  if (!gTestOutputMode) {
+    std::vector<const char*> platform = GetPlatformClangArguments();
+    for (auto arg: platform)
+      result.args.push_back(arg);
+  }
+
   bool next_flag_is_path = false;
   bool add_next_flag_to_quote_dirs = false;
   bool add_next_flag_to_angle_dirs = false;
diff --git a/src/serializer.cc b/src/serializer.cc
index 07db20de..02f8fd3c 100644
--- a/src/serializer.cc
+++ b/src/serializer.cc
@@ -10,9 +10,7 @@
 
 #include <stdexcept>
 
-namespace {
 bool gTestOutputMode = false;
-}  // namespace
 
 //// Elementary types